Shell Bell doesn't get off the train immediately when they hit District Three. Tony has one last miserable speech to deliver, and the train will then stick around long enough for everything to be unloaded. Bell sits tight in Sherlock's compartment with the TV on, keeps her wits about her, and awaits cues from either Stark twin.
If Sherlock is still awake at this eventuality, she will notice that Bell says random words in her sleep. "Sand. Twirling. Cork."
Eventually, despite the soundtrack, she falls asleep too.
She might want to carry on snuggling anyway just because it's physically pleasant and she's gone for a significant fraction of her life without human contact. But she doesn't want it to be weird.
She scoots away carefully and extricates herself, attempting to not wake Sherlock, not sure if Sherlock's sleep thing will "notice" while she's still asleep that the dart has worn off and Bell is no longer an acceptable sleep companion.
When Sherlock wakes up again, a few minutes later, she doesn't exhibit any signs of distress.
"Still not awful to have me in the room while you were asleep?" Bell asks, yawning.
"That's good. That was so strange," says Bell. "I'm almost afraid to go back out again. There's no clock in here, that awful holiday might still be going on."
"Good riddance," declares Bell, getting up to leave the room. "Let's clear my room of fascinating useful things and put them in your basement."
Out the door they go.
Bell points out the parts of the generator that were referred to during various parts of the explanation she got - the ports to attach batteries, in particular. She also produces her gold coins. "I got some of these, if there's a reason to want gold instead of copper for anything," she says.
"Shiny," Tony says approvingly. He scoops up generator, coins, and batteries. "I'll just go and get to know these guys better."
"We have a guest room that has yet to see an actual guest," she says. "Would that suit?"
The house is not enormous, but it is definitely unnecessarily large.
"This is a nice place," says Bell. "Do I need to avoid going outside?"